1. Technical Field
The present invention relates to a printer having a paper cassette and, in particular, to an envelope pressing device in a printer. The pressing device presses down on the closure flaps of envelopes with a predetermined force when the envelopes are fed.
2. Related Art
Generally, a printer is equipped with a paper cassette for feeding paper. The paper cassette is loaded with a stack of paper, and is inserted into a printer body. The paper is transferred by a transferring device sheet by sheet, and then images are formed on the paper by an image forming portion of the printer. Guides are provided in the paper cassette for regulating placement of papers of different sizes. An envelope mounting portion is defined at a portion of a paper plate in the paper cassette. A plurality of envelopes stacked in the paper cassette are fed one by one to the printer body by rotation of a pickup roller.
However, the closure flap of an envelope is likely to be unfolded upward while the envelope is being fed. As a result, the envelope may skew or jam, causing mis-feeding.
The following patents are considered to be representative of the prior art, and are burdened by the disadvantages set forth herein: U.S. Pat. No. 4,340,314 to Berger, entitled Envelope Feeding Apparatus, U.S. Pat. No. 4,431,323 to Kulow, entitled Envelope Feeder Method And Apparatus, U.S. Pat. No. 4,362,100 to Wu et al., entitled Envelope Feeder, U.S. Pat. No. 4,511,135 to Huerta et al., entitled Enhanced Envelope Feeding, U.S. Pat. No. 4,522,382 to Chu et al., entitled Sheet And Envelope Feed Apparatus For A Printer And Associated Methods, U.S. Pat. No. 4,585,223 to Tam, entitled Envelope Feeder, U.S. Pat. No. 4,763,575 to Miciukiewicz, entitled Envelope Pressure Plate For Mailing Machine, U.S. Pat. No. 4,603,846 to Miles, entitled Dual-Stream Envelope Feeder, U.S. Pat. No. 4,640,502 to Habich et al., entitled Envelope Hopper For Feed And Delivery, U.S. Pat. No. 4,733,310 to Kapp et al., entitled Paper Sheet And Envelope Feeder Apparatus, U.S. Pat. No. 4,843,962 to Neelman et al., entitled Double-Feed Envelope Guide System For Printing Press, U.S. Pat. No. 4,930,762 to Kitchens, entitled Portable Envelope Feeder, U.S. Pat. No. 5,026,042 to Miller, entitled Sheet Feeder For Copiers And Printers, U.S. Pat. No. 5,069,434 to Sellers, entitled Removable Dual Bin Envelope Feed Tray For AN Image Reproduction Machine, U.S. Pat. No. 5,295,674 to Zoltner, entitled High Capacity Envelope Stacker Apparatus, U.S. Pat. No. 5,419,645 to Russo, entitled Envelope Cassette Tray, U.S. Pat. No. 5,450,187 to Pei et al., entitled Envelope Processing IN A Laser Printer For Higher Reliability, Usability And Throughput, U.S. Pat. No. 5,527,029 to Bortolotti et al., entitled Device For Introducing sheets Or Envelopes Into A Printer, U.S. Pat. No. 5,520,381 to Lo et al., entitled High Capacity, Low Jam Envelope Feeder For Laser Printer, and U.S. Pat. No. 5,755,433 to Klein, entitled Method And Apparatus For High Speed Envelope Printing.